Long-term Survival of Southern Chinese Patients With Systemic Lupus Erythematosus

Abstract

We conducted the current study to determine the clinical determinants of survival and the survival rates in an unselected cohort of Chinese patients with new-onset systemic lupus erythematosus (SLE), including all age-groups. Patients were those newly diagnosed as having SLE or referred within 6 months of diagnosis to the departments of medicine, geriatrics, and pediatrics at Tuen Mun Hospital, Hong Kong, between 1991 and 2003. Patients under the care of all specialists were included for analysis. We obtained demographic data, presenting and cumulative clinical features, disease activity, and serial damage scores. For patients who died or were lost to follow-up, data were censored at the last clinic visit. Survival over time was studied by the Kaplan-Meier method, and factors predictive of mortality were evaluated by the Cox proportional hazard model. We studied 285 new-onset SLE patients (92% women). All were ethnic Chinese and fulfilled at least 4 of the American College of Rheumatology criteria for SLE. The mean age of SLE onset was 30.0 +/- 13.5 years. Fifty (18%) patients had first onset of SLE before the age of 16 years (childhood onset), and 22 (8%) had disease onset after the age of 50 years (late onset); 213 (75%) patients had disease onset between the ages of 16 and 50 years (adult onset). Twenty-nine (10%) patients died (4 from the childhood-onset group, 6 from the late-onset group, and 19 from the adult-onset group) and 18 (6%) patients were lost to follow-up. The overall 5-, 10-, and 15-year survival rates were 92%, 83%, and 80%, respectively. Survival was significantly worse in late-onset patients: 5-, 10-, and 15-year survival rates were 66%, 44%, and 44%, respectively; p < 0.0001. Infection was the main cause of death (55%), followed by cardiovascular (17%) and cerebrovascular complications (14%). Unfavorable factors for survival on univariate analysis were increasing age, damage scores at 1 year, and the use of high-dose corticosteroids. Cox regression revealed that damage scores at 1 year and hematologic manifestations were independent predictors of mortality. Long-term survival of Chinese SLE patients is comparable to that reported for white patients in the 1990s. Late-onset SLE patients have the worst prognosis. Early damage predicts mortality.